1. Field of the Invention
The present invention relates to an apparatus for controlling bending of a bendable portion of the insert part of an endoscope. More particularly, the present invention pertains to a bending control apparatus for an endoscope which is designed so that a pulley which is wound with a control wire is rotated with a manual control device to pull the control wire to thereby bend the bendable portion.
2. Description of the Related Art
In a typical conventional apparatus of the type described above, a manual control means such as a manual control lever which is used to rotate the pulley is connected directly to the rotary shaft of the pulley. Accordingly, the angle of rotation of the pulley is coincident with that of the manual control means.
However, the maximum effective angle of rotation of a manual control means such as a manual control lever is generally limited to a relatively small angle from the viewpoint of structure or controllability. Accordingly, the diameter of the pulley must be increased in order to increase the angle at which the bendable portion is bent, which results in an increase in the overall size of the control part and hence causes the operability to be impaired a great deal.